/**
 * @file llworld.cpp
 * @brief Initial test structure to organize viewer regions
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "llviewerprecompiledheaders.h"

#include "llworld.h"
#include "llrender.h"

#include "indra_constants.h"
#include "llstl.h"

#include "llagent.h"
#include "llagentcamera.h"
#include "llviewercontrol.h"
#include "lldrawpool.h"
#include "llglheaders.h"
#include "llhttpnode.h"
#include "llregionhandle.h"
#include "llsky.h"
#include "llsurface.h"
#include "lltrans.h"
#include "llviewercamera.h"
#include "llviewertexture.h"
#include "llviewertexturelist.h"
#include "llviewernetwork.h"
#include "llviewerobjectlist.h"
#include "llviewerparceloverlay.h"
#include "llviewerregion.h"
#include "llviewerstats.h"
#include "llvlcomposition.h"
#include "llvoavatar.h"
#include "llvocache.h"
#include "llvowater.h"
#include "message.h"
#include "pipeline.h"
#include "llappviewer.h"        // for do_disconnect()
#include "llscenemonitor.h"
#include <deque>
#include <queue>
#include <map>
#include <cstring>


//
// Globals
//
U32         gAgentPauseSerialNum = 0;

//
// Constants
//
const S32 WORLD_PATCH_SIZE = 16;

extern LLColor4U MAX_WATER_COLOR;

const U32 LLWorld::mWidth = 256;

// meters/point, therefore mWidth * mScale = meters per edge
const F32 LLWorld::mScale = 1.f;

const F32 LLWorld::mWidthInMeters = mWidth * mScale;

//
// Functions
//

// allocate the stack
LLWorld::LLWorld() :
    mLandFarClip(DEFAULT_FAR_PLANE),
    mLastPacketsIn(0),
    mLastPacketsOut(0),
    mLastPacketsLost(0),
    mSpaceTimeUSec(0)
{
    for (S32 i = 0; i < EDGE_WATER_OBJECTS_COUNT; i++)
    {
        mEdgeWaterObjects[i] = NULL;
    }

    LLPointer<LLImageRaw> raw = new LLImageRaw(1,1,4);
    U8 *default_texture = raw->getData();
    *(default_texture++) = MAX_WATER_COLOR.mV[0];
    *(default_texture++) = MAX_WATER_COLOR.mV[1];
    *(default_texture++) = MAX_WATER_COLOR.mV[2];
    *(default_texture++) = MAX_WATER_COLOR.mV[3];

    mDefaultWaterTexturep = LLViewerTextureManager::getLocalTexture(raw.get(), false);
    gGL.getTexUnit(0)->bind(mDefaultWaterTexturep);
    mDefaultWaterTexturep->setAddressMode(LLTexUnit::TAM_CLAMP);

    LLViewerRegion::sVOCacheCullingEnabled = gSavedSettings.getBOOL("RequestFullRegionCache") && gSavedSettings.getBOOL("ObjectCacheEnabled");
}


void LLWorld::resetClass()
{
    mHoleWaterObjects.clear();
    gObjectList.destroy();
    gSky.cleanup(); // references an object
    for(region_list_t::iterator region_it = mRegionList.begin(); region_it != mRegionList.end(); )
    {
        LLViewerRegion* region_to_delete = *region_it++;
        removeRegion(region_to_delete->getHost());
    }

    LLViewerPartSim::getInstance()->destroyClass();

    mDefaultWaterTexturep = NULL ;
    for (S32 i = 0; i < EDGE_WATER_OBJECTS_COUNT; i++)
    {
        mEdgeWaterObjects[i] = NULL;
    }

    //make all visible drawbles invisible.
    LLDrawable::incrementVisible();

    LLSceneMonitor::deleteSingleton();
}


LLViewerRegion* LLWorld::addRegion(const U64 &region_handle, const LLHost &host)
{
    LL_INFOS() << "Add region with handle: " << region_handle << " on host " << host << LL_ENDL;
    LLViewerRegion *regionp = getRegionFromHandle(region_handle);
    std::string seedUrl;
    if (regionp)
    {
        LLHost old_host = regionp->getHost();
        // region already exists!
        if (host == old_host && regionp->isAlive())
        {
            // This is a duplicate for the same host and it's alive, don't bother.
            LL_INFOS() << "Region already exists and is alive, using existing region" << LL_ENDL;
            return regionp;
        }

        if (host != old_host)
        {
            LL_WARNS() << "LLWorld::addRegion exists, but old host " << old_host
                    << " does not match new host " << host
                    << ", removing old region and creating new" << LL_ENDL;
        }
        if (!regionp->isAlive())
        {
            LL_WARNS() << "LLWorld::addRegion exists, but isn't alive. Removing old region and creating new" << LL_ENDL;
        }

        // Save capabilities seed URL
        seedUrl = regionp->getCapability("Seed");

        // Kill the old host, and then we can continue on and add the new host.  We have to kill even if the host
        // matches, because all the agent state for the new camera is completely different.
        removeRegion(old_host);
    }
    else
    {
        LL_INFOS() << "Region does not exist, creating new one" << LL_ENDL;
    }

    U32 iindex = 0;
    U32 jindex = 0;
    from_region_handle(region_handle, &iindex, &jindex);
    S32 x = (S32)(iindex/mWidth);
    S32 y = (S32)(jindex/mWidth);
    LL_INFOS() << "Adding new region (" << x << ":" << y << ")"
        << " on host: " << host << LL_ENDL;

    LLVector3d origin_global;

    origin_global = from_region_handle(region_handle);

    regionp = new LLViewerRegion(region_handle,
                                    host,
                                    mWidth,
                                    WORLD_PATCH_SIZE,
                                    getRegionWidthInMeters() );
    if (!regionp)
    {
        LL_ERRS() << "Unable to create new region!" << LL_ENDL;
    }

    if ( !seedUrl.empty() )
    {
        regionp->setCapability("Seed", seedUrl);
    }

    mRegionList.push_back(regionp);
    mActiveRegionList.push_back(regionp);
    mCulledRegionList.push_back(regionp);


    // Find all the adjacent regions, and attach them.
    // Generate handles for all of the adjacent regions, and attach them in the correct way.
    // connect the edges
    F32 adj_x = 0.f;
    F32 adj_y = 0.f;
    F32 region_x = 0.f;
    F32 region_y = 0.f;
    U64 adj_handle = 0;

    F32 width = getRegionWidthInMeters();

    LLViewerRegion *neighborp;
    from_region_handle(region_handle, &region_x, &region_y);

    // Iterate through all directions, and connect neighbors if there.
    S32 dir;
    for (dir = 0; dir < 8; dir++)
    {
        adj_x = region_x + width * gDirAxes[dir][0];
        adj_y = region_y + width * gDirAxes[dir][1];
        to_region_handle(adj_x, adj_y, &adj_handle);

        neighborp = getRegionFromHandle(adj_handle);
        if (neighborp)
        {
            //LL_INFOS() << "Connecting " << region_x << ":" << region_y << " -> " << adj_x << ":" << adj_y << LL_ENDL;
            regionp->connectNeighbor(neighborp, dir);
        }
    }

    updateWaterObjects();

    return regionp;
}


void LLWorld::removeRegion(const LLHost &host)
{
    F32 x, y;

    LLViewerRegion *regionp = getRegion(host);
    if (!regionp)
    {
        LL_WARNS() << "Trying to remove region that doesn't exist!" << LL_ENDL;
        return;
    }

    if (regionp == gAgent.getRegion())
    {
        for (region_list_t::iterator iter = mRegionList.begin();
             iter != mRegionList.end(); ++iter)
        {
            LLViewerRegion* reg = *iter;
            LL_WARNS() << "RegionDump: " << reg->getName()
                << " " << reg->getHost()
                << " " << reg->getOriginGlobal()
                << LL_ENDL;
        }

        LL_WARNS() << "Agent position global " << gAgent.getPositionGlobal()
            << " agent " << gAgent.getPositionAgent()
            << LL_ENDL;

        LL_WARNS() << "Regions visited " << gAgent.getRegionsVisited() << LL_ENDL;

        LL_WARNS() << "gFrameTimeSeconds " << gFrameTimeSeconds << LL_ENDL;

        LL_WARNS() << "Disabling region " << regionp->getName() << " that agent is in!" << LL_ENDL;
        LLAppViewer::instance()->forceDisconnect(LLTrans::getString("YouHaveBeenDisconnected"));

        regionp->saveObjectCache() ; //force to save objects here in case that the object cache is about to be destroyed.
        return;
    }

    from_region_handle(regionp->getHandle(), &x, &y);
    LL_INFOS() << "Removing region " << x << ":" << y << LL_ENDL;

    mRegionList.remove(regionp);
    mActiveRegionList.remove(regionp);
    mCulledRegionList.remove(regionp);
    mVisibleRegionList.remove(regionp);

    mRegionRemovedSignal(regionp);

    updateWaterObjects();

    //double check all objects of this region are removed.
    gObjectList.clearAllMapObjectsInRegion(regionp) ;
    //llassert_always(!gObjectList.hasMapObjectInRegion(regionp)) ;

    delete regionp; // Delete last to prevent use after free
}


LLViewerRegion* LLWorld::getRegion(const LLHost &host)
{
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        if (regionp->getHost() == host)
        {
            return regionp;
        }
    }
    return NULL;
}

LLViewerRegion* LLWorld::getRegionFromPosAgent(const LLVector3 &pos)
{
    return getRegionFromPosGlobal(gAgent.getPosGlobalFromAgent(pos));
}

LLViewerRegion* LLWorld::getRegionFromPosGlobal(const LLVector3d &pos)
{
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        if (regionp->pointInRegionGlobal(pos))
        {
            return regionp;
        }
    }
    return NULL;
}


LLVector3d  LLWorld::clipToVisibleRegions(const LLVector3d &start_pos, const LLVector3d &end_pos)
{
    if (positionRegionValidGlobal(end_pos))
    {
        return end_pos;
    }

    LLViewerRegion* regionp = getRegionFromPosGlobal(start_pos);
    if (!regionp)
    {
        return start_pos;
    }

    LLVector3d delta_pos = end_pos - start_pos;
    LLVector3d delta_pos_abs;
    delta_pos_abs.setVec(delta_pos);
    delta_pos_abs.abs();

    LLVector3 region_coord = regionp->getPosRegionFromGlobal(end_pos);
    F64 clip_factor = 1.0;
    F32 region_width = regionp->getWidth();
    if (region_coord.mV[VX] < 0.f)
    {
        if (region_coord.mV[VY] < region_coord.mV[VX])
        {
            // clip along y -
            clip_factor = -(region_coord.mV[VY] / delta_pos_abs.mdV[VY]);
        }
        else
        {
            // clip along x -
            clip_factor = -(region_coord.mV[VX] / delta_pos_abs.mdV[VX]);
        }
    }
    else if (region_coord.mV[VX] > region_width)
    {
        if (region_coord.mV[VY] > region_coord.mV[VX])
        {
            // clip along y +
            clip_factor = (region_coord.mV[VY] - region_width) / delta_pos_abs.mdV[VY];
        }
        else
        {
            //clip along x +
            clip_factor = (region_coord.mV[VX] - region_width) / delta_pos_abs.mdV[VX];
        }
    }
    else if (region_coord.mV[VY] < 0.f)
    {
        // clip along y -
        clip_factor = -(region_coord.mV[VY] / delta_pos_abs.mdV[VY]);
    }
    else if (region_coord.mV[VY] > region_width)
    {
        // clip along y +
        clip_factor = (region_coord.mV[VY] - region_width) / delta_pos_abs.mdV[VY];
    }

    // clamp to within region dimensions
    LLVector3d final_region_pos = LLVector3d(region_coord) - (delta_pos * clip_factor);
    final_region_pos.mdV[VX] = llclamp(final_region_pos.mdV[VX], 0.0,
                                       (F64)(region_width - F_ALMOST_ZERO));
    final_region_pos.mdV[VY] = llclamp(final_region_pos.mdV[VY], 0.0,
                                       (F64)(region_width - F_ALMOST_ZERO));
    final_region_pos.mdV[VZ] = llclamp(final_region_pos.mdV[VZ], 0.0,
                                       (F64)(LLWorld::getInstance()->getRegionMaxHeight() - F_ALMOST_ZERO));
    return regionp->getPosGlobalFromRegion(LLVector3(final_region_pos));
}

LLViewerRegion* LLWorld::getRegionFromHandle(const U64 &handle)
{
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        if (regionp->getHandle() == handle)
        {
            return regionp;
        }
    }
    return NULL;
}

LLViewerRegion* LLWorld::getRegionFromID(const LLUUID& region_id)
{
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        if (regionp->getRegionID() == region_id)
        {
            return regionp;
        }
    }
    return NULL;
}

void LLWorld::updateAgentOffset(const LLVector3d &offset_global)
{
#if 0
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        regionp->setAgentOffset(offset_global);
    }
#endif
}


bool LLWorld::positionRegionValidGlobal(const LLVector3d &pos_global)
{
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        if (regionp->pointInRegionGlobal(pos_global))
        {
            return true;
        }
    }
    return false;
}


// Allow objects to go up to their radius underground.
F32 LLWorld::getMinAllowedZ(LLViewerObject* object, const LLVector3d &global_pos)
{
    F32 land_height = resolveLandHeightGlobal(global_pos);
    F32 radius = 0.5f * object->getScale().length();
    return land_height - radius;
}



LLViewerRegion* LLWorld::resolveRegionGlobal(LLVector3 &pos_region, const LLVector3d &pos_global)
{
    LLViewerRegion *regionp = getRegionFromPosGlobal(pos_global);

    if (regionp)
    {
        pos_region = regionp->getPosRegionFromGlobal(pos_global);
        return regionp;
    }

    return NULL;
}


LLViewerRegion* LLWorld::resolveRegionAgent(LLVector3 &pos_region, const LLVector3 &pos_agent)
{
    LLVector3d pos_global = gAgent.getPosGlobalFromAgent(pos_agent);
    LLViewerRegion *regionp = getRegionFromPosGlobal(pos_global);

    if (regionp)
    {
        pos_region = regionp->getPosRegionFromGlobal(pos_global);
        return regionp;
    }

    return NULL;
}


F32 LLWorld::resolveLandHeightAgent(const LLVector3 &pos_agent)
{
    LLVector3d pos_global = gAgent.getPosGlobalFromAgent(pos_agent);
    return resolveLandHeightGlobal(pos_global);
}


F32 LLWorld::resolveLandHeightGlobal(const LLVector3d &pos_global)
{
    LLViewerRegion *regionp = getRegionFromPosGlobal(pos_global);
    if (regionp)
    {
        return regionp->getLand().resolveHeightGlobal(pos_global);
    }
    return 0.0f;
}


// Takes a line defined by "point_a" and "point_b" and determines the closest (to point_a)
// point where the the line intersects an object or the land surface.  Stores the results
// in "intersection" and "intersection_normal" and returns a scalar value that represents
// the normalized distance along the line from "point_a" to "intersection".
//
// Currently assumes point_a and point_b only differ in z-direction,
// but it may eventually become more general.
F32 LLWorld::resolveStepHeightGlobal(const LLVOAvatar* avatarp, const LLVector3d &point_a, const LLVector3d &point_b,
                               LLVector3d &intersection, LLVector3 &intersection_normal,
                               LLViewerObject **viewerObjectPtr)
{
    // initialize return value to null
    if (viewerObjectPtr)
    {
        *viewerObjectPtr = NULL;
    }

    LLViewerRegion *regionp = getRegionFromPosGlobal(point_a);
    if (!regionp)
    {
        // We're outside the world
        intersection = 0.5f * (point_a + point_b);
        intersection_normal.setVec(0.0f, 0.0f, 1.0f);
        return 0.5f;
    }

    // calculate the length of the segment
    F32 segment_length = (F32)((point_a - point_b).length());
    if (0.0f == segment_length)
    {
        intersection = point_a;
        intersection_normal.setVec(0.0f, 0.0f, 1.0f);
        return segment_length;
    }

    // get land height
    // Note: we assume that the line is parallel to z-axis here
    LLVector3d land_intersection = point_a;
    F32 normalized_land_distance;

    land_intersection.mdV[VZ] = regionp->getLand().resolveHeightGlobal(point_a);
    normalized_land_distance = (F32)(point_a.mdV[VZ] - land_intersection.mdV[VZ]) / segment_length;
    intersection = land_intersection;
    intersection_normal = resolveLandNormalGlobal(land_intersection);

    if (avatarp && !avatarp->mFootPlane.isExactlyClear())
    {
        LLVector3 foot_plane_normal(avatarp->mFootPlane.mV);
        LLVector3 start_pt = avatarp->getRegion()->getPosRegionFromGlobal(point_a);
        // added 0.05 meters to compensate for error in foot plane reported by Havok
        F32 norm_dist_from_plane = ((start_pt * foot_plane_normal) - avatarp->mFootPlane.mV[VW]) + 0.05f;
        norm_dist_from_plane = llclamp(norm_dist_from_plane / segment_length, 0.f, 1.f);
        if (norm_dist_from_plane < normalized_land_distance)
        {
            // collided with object before land
            normalized_land_distance = norm_dist_from_plane;
            intersection = point_a;
            intersection.mdV[VZ] -= norm_dist_from_plane * segment_length;
            intersection_normal = foot_plane_normal;
        }
        else
        {
            intersection = land_intersection;
            intersection_normal = resolveLandNormalGlobal(land_intersection);
        }
    }

    return normalized_land_distance;
}


LLSurfacePatch * LLWorld::resolveLandPatchGlobal(const LLVector3d &pos_global)
{
    //  returns a pointer to the patch at this location
    LLViewerRegion *regionp = getRegionFromPosGlobal(pos_global);
    if (!regionp)
    {
        return NULL;
    }

    return regionp->getLand().resolvePatchGlobal(pos_global);
}


LLVector3 LLWorld::resolveLandNormalGlobal(const LLVector3d &pos_global)
{
    LLViewerRegion *regionp = getRegionFromPosGlobal(pos_global);
    if (!regionp)
    {
        return LLVector3::z_axis;
    }

    return regionp->getLand().resolveNormalGlobal(pos_global);
}


void LLWorld::updateVisibilities()
{
    F32 cur_far_clip = LLViewerCamera::getInstance()->getFar();

    // Go through the culled list and check for visible regions (region is visible if land is visible)
    for (region_list_t::iterator iter = mCulledRegionList.begin();
         iter != mCulledRegionList.end(); )
    {
        region_list_t::iterator curiter = iter++;
        LLViewerRegion* regionp = *curiter;

        LLSpatialPartition* part = regionp->getSpatialPartition(LLViewerRegion::PARTITION_TERRAIN);
        if (part)
        {
            LLSpatialGroup* group = (LLSpatialGroup*) part->mOctree->getListener(0);
            const LLVector4a* bounds = group->getBounds();
            if (LLViewerCamera::getInstance()->AABBInFrustum(bounds[0], bounds[1]))
            {
                mCulledRegionList.erase(curiter);
                mVisibleRegionList.push_back(regionp);
            }
        }
    }

    // Update all of the visible regions
    for (region_list_t::iterator iter = mVisibleRegionList.begin();
         iter != mVisibleRegionList.end(); )
    {
        region_list_t::iterator curiter = iter++;
        LLViewerRegion* regionp = *curiter;
        if (!regionp->getLand().hasZData())
        {
            continue;
        }

        LLSpatialPartition* part = regionp->getSpatialPartition(LLViewerRegion::PARTITION_TERRAIN);
        if (part)
        {
            LLSpatialGroup* group = (LLSpatialGroup*) part->mOctree->getListener(0);
            const LLVector4a* bounds = group->getBounds();
            if (LLViewerCamera::getInstance()->AABBInFrustum(bounds[0], bounds[1]))
            {
                regionp->calculateCameraDistance();
                regionp->getLand().updatePatchVisibilities(gAgent);
            }
            else
            {
                mVisibleRegionList.erase(curiter);
                mCulledRegionList.push_back(regionp);
            }
        }
    }

    // Sort visible regions
    mVisibleRegionList.sort(LLViewerRegion::CompareDistance());

    LLViewerCamera::getInstance()->setFar(cur_far_clip);
}

static LLTrace::SampleStatHandle<> sNumActiveCachedObjects("numactivecachedobjects", "Number of objects loaded from cache");

void LLWorld::updateRegions(F32 max_update_time)
{
    LL_PROFILE_ZONE_SCOPED;
    LLTimer update_timer;
    mNumOfActiveCachedObjects = 0;

    if(LLViewerCamera::getInstance()->isChanged())
    {
        LLViewerRegion::sLastCameraUpdated = LLViewerOctreeEntryData::getCurrentFrame() + 1;
    }
    LLViewerRegion::calcNewObjectCreationThrottle();
    if(LLViewerRegion::isNewObjectCreationThrottleDisabled())
    {
        max_update_time = llmax(max_update_time, 1.0f); //seconds, loosen the time throttle.
    }

    F32 max_time = llmin((F32)(max_update_time - update_timer.getElapsedTimeF32()), max_update_time * 0.25f);
    //update the self avatar region
    LLViewerRegion* self_regionp = gAgent.getRegion();
    if(self_regionp)
    {
        self_regionp->idleUpdate(max_time);
    }

    //sort regions by its mLastUpdate
    //smaller mLastUpdate first to make sure every region has chance to get updated.
    LLViewerRegion::region_priority_list_t region_list;
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        if(regionp != self_regionp)
        {
            region_list.insert(regionp);
        }
        mNumOfActiveCachedObjects += regionp->getNumOfActiveCachedObjects();
    }

    // Perform idle time updates for the regions (and associated surfaces)
    for (LLViewerRegion::region_priority_list_t::iterator iter = region_list.begin();
         iter != region_list.end(); ++iter)
    {
        if(max_time > 0.f)
        {
            max_time = llmin((F32)(max_update_time - update_timer.getElapsedTimeF32()), max_update_time * 0.25f);
        }

        if(max_time > 0.f)
        {
            (*iter)->idleUpdate(max_time);
        }
        else
        {
            //perform some necessary but very light updates.
            (*iter)->lightIdleUpdate();
        }
    }

    if(max_time > 0.f)
    {
        max_time = llmin((F32)(max_update_time - update_timer.getElapsedTimeF32()), max_update_time * 0.25f);
    }
    if(max_time > 0.f)
    {
        LLViewerRegion::idleCleanup(max_time);
    }

    sample(sNumActiveCachedObjects, mNumOfActiveCachedObjects);
}

void LLWorld::clearAllVisibleObjects()
{
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        //clear all cached visible objects.
        (*iter)->clearCachedVisibleObjects();
    }
    clearHoleWaterObjects();
    clearEdgeWaterObjects();
}

void LLWorld::updateParticles()
{
    LLViewerPartSim::getInstance()->updateSimulation();
}

void LLWorld::renderPropertyLines()
{
    for (region_list_t::iterator iter = mVisibleRegionList.begin();
         iter != mVisibleRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        regionp->renderPropertyLines();
    }
}


void LLWorld::updateNetStats()
{
    F64Bits bits;

    for (region_list_t::iterator iter = mActiveRegionList.begin();
         iter != mActiveRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        regionp->updateNetStats();
        bits += regionp->mBitsReceived;
        regionp->mBitsReceived = (F32Bits)0.f;
        regionp->mPacketsReceived = 0.f;
    }

    S32 packets_in = gMessageSystem->mPacketsIn - mLastPacketsIn;
    S32 packets_out = gMessageSystem->mPacketsOut - mLastPacketsOut;
    S32 packets_lost = gMessageSystem->mDroppedPackets - mLastPacketsLost;

    F64Bits actual_in_bits(gMessageSystem->mPacketRing.getAndResetActualInBits());
    F64Bits actual_out_bits(gMessageSystem->mPacketRing.getAndResetActualOutBits());

    add(LLStatViewer::MESSAGE_SYSTEM_DATA_IN, actual_in_bits);
    add(LLStatViewer::MESSAGE_SYSTEM_DATA_OUT, actual_out_bits);
    add(LLStatViewer::ACTIVE_MESSAGE_DATA_RECEIVED, bits);
    add(LLStatViewer::PACKETS_IN, packets_in);
    add(LLStatViewer::PACKETS_OUT, packets_out);
    add(LLStatViewer::PACKETS_LOST, packets_lost);

    F32 total_packets_in = (F32)LLViewerStats::instance().getRecording().getSum(LLStatViewer::PACKETS_IN);
    if (total_packets_in > 0.f)
    {
        F32 total_packets_lost = (F32)LLViewerStats::instance().getRecording().getSum(LLStatViewer::PACKETS_LOST);
        sample(LLStatViewer::PACKETS_LOST_PERCENT, LLUnits::Ratio::fromValue((F32)total_packets_lost/(F32)total_packets_in));
    }

    mLastPacketsIn = gMessageSystem->mPacketsIn;
    mLastPacketsOut = gMessageSystem->mPacketsOut;
    mLastPacketsLost = gMessageSystem->mDroppedPackets;
}


void LLWorld::printPacketsLost()
{
    LL_INFOS() << "Simulators:" << LL_ENDL;
    LL_INFOS() << "----------" << LL_ENDL;

    LLCircuitData *cdp = NULL;
    for (region_list_t::iterator iter = mActiveRegionList.begin();
         iter != mActiveRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        cdp = gMessageSystem->mCircuitInfo.findCircuit(regionp->getHost());
        if (cdp)
        {
            LLVector3d range = regionp->getCenterGlobal() - gAgent.getPositionGlobal();

            LL_INFOS() << regionp->getHost() << ", range: " << range.length()
                    << " packets lost: " << cdp->getPacketsLost() << LL_ENDL;
        }
    }
}

void LLWorld::processCoarseUpdate(LLMessageSystem* msg, void** user_data)
{
    LLViewerRegion* region = LLWorld::getInstance()->getRegion(msg->getSender());
    if( region )
    {
        region->updateCoarseLocations(msg);
    }
}

F32 LLWorld::getLandFarClip() const
{
    return mLandFarClip;
}

void LLWorld::setLandFarClip(const F32 far_clip)
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_ENVIRONMENT;
    static S32 const rwidth = (S32)REGION_WIDTH_U32;
    S32 const n1 = (llceil(mLandFarClip) - 1) / rwidth;
    S32 const n2 = (llceil(far_clip) - 1) / rwidth;
    bool need_water_objects_update = n1 != n2;

    mLandFarClip = far_clip;

    if (need_water_objects_update)
    {
        updateWaterObjects();
    }
}

// Some region that we're connected to, but not the one we're in, gave us
// a (possibly) new water height. Update it in our local copy.
void LLWorld::waterHeightRegionInfo(std::string const& sim_name, F32 water_height)
{
    for (region_list_t::iterator iter = mRegionList.begin(); iter != mRegionList.end(); ++iter)
    {
        if ((*iter)->getName() == sim_name)
        {
            (*iter)->setWaterHeight(water_height);
            break;
        }
    }
}

void LLWorld::clearHoleWaterObjects()
{
    for (std::list<LLPointer<LLVOWater> >::iterator iter = mHoleWaterObjects.begin();
        iter != mHoleWaterObjects.end(); ++iter)
    {
        LLVOWater* waterp = (*iter).get();
        gObjectList.killObject(waterp);
    }
    mHoleWaterObjects.clear();
}

void LLWorld::clearEdgeWaterObjects()
{
    for (S32 i = 0; i < EDGE_WATER_OBJECTS_COUNT; i++)
    {
        gObjectList.killObject(mEdgeWaterObjects[i]);
        mEdgeWaterObjects[i] = NULL;
    }
}

void LLWorld::updateWaterObjects()
{
    if (!gAgent.getRegion())
    {
        return;
    }
    if (mRegionList.empty())
    {
        LL_WARNS() << "No regions!" << LL_ENDL;
        return;
    }

    // First, determine the min and max "box" of water objects
    S32 min_x = 0;
    S32 min_y = 0;
    S32 max_x = 0;
    S32 max_y = 0;
    U32 region_x, region_y;

    S32 rwidth = 256;

    // We only want to fill in water for stuff that's near us, say, within 256 or 512m
    S32 range = LLViewerCamera::getInstance()->getFar() > 256.f ? 512 : 256;

    LLViewerRegion* regionp = gAgent.getRegion();
    from_region_handle(regionp->getHandle(), &region_x, &region_y);

    min_x = (S32)region_x - range;
    min_y = (S32)region_y - range;
    max_x = (S32)region_x + range;
    max_y = (S32)region_y + range;

    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        LLVOWater* waterp = regionp->getLand().getWaterObj();
        if (waterp)
        {
            gObjectList.updateActive(waterp);
        }
    }

    clearHoleWaterObjects();

    // Use the water height of the region we're on for areas where there is no region
    F32 water_height = gAgent.getRegion()->getWaterHeight();

    // Now, get a list of the holes
    S32 x, y;
    for (x = min_x; x <= max_x; x += rwidth)
    {
        for (y = min_y; y <= max_y; y += rwidth)
        {
            U64 region_handle = to_region_handle(x, y);
            if (!getRegionFromHandle(region_handle))
            {   // No region at that area, so make water
                LLVOWater* waterp = (LLVOWater *)gObjectList.createObjectViewer(LLViewerObject::LL_VO_WATER, gAgent.getRegion());
                waterp->setPositionGlobal(LLVector3d(x + rwidth/2,
                                                     y + rwidth/2,
                                                     256.f + water_height));
                waterp->setScale(LLVector3((F32)rwidth, (F32)rwidth, 512.f));
                gPipeline.createObject(waterp);
                mHoleWaterObjects.push_back(waterp);
            }
        }
    }

    // Update edge water objects
    S32 wx, wy;
    S32 center_x, center_y;
    wx = (max_x - min_x) + rwidth;
    wy = (max_y - min_y) + rwidth;
    center_x = min_x + (wx >> 1);
    center_y = min_y + (wy >> 1);

    S32 add_boundary[4] = {
        (S32)(512 - (max_x - region_x)),
        (S32)(512 - (max_y - region_y)),
        (S32)(512 - (region_x - min_x)),
        (S32)(512 - (region_y - min_y)) };

    S32 dir;
    for (dir = 0; dir < EDGE_WATER_OBJECTS_COUNT; dir++)
    {
        S32 dim[2] = { 0 };
        switch (gDirAxes[dir][0])
        {
        case -1: dim[0] = add_boundary[2]; break;
        case  0: dim[0] = wx; break;
        default: dim[0] = add_boundary[0]; break;
        }
        switch (gDirAxes[dir][1])
        {
        case -1: dim[1] = add_boundary[3]; break;
        case  0: dim[1] = wy; break;
        default: dim[1] = add_boundary[1]; break;
        }

        // Resize and reshape the water objects
        const S32 water_center_x = center_x + ll_round((wx + dim[0]) * 0.5f * gDirAxes[dir][0]);
        const S32 water_center_y = center_y + ll_round((wy + dim[1]) * 0.5f * gDirAxes[dir][1]);

        LLVOWater* waterp = mEdgeWaterObjects[dir];
        if (!waterp || waterp->isDead())
        {
            // The edge water objects can be dead because they're attached to the region that the
            // agent was in when they were originally created.
            mEdgeWaterObjects[dir] = (LLVOWater *)gObjectList.createObjectViewer(LLViewerObject::LL_VO_VOID_WATER,
                                                                                 gAgent.getRegion());
            waterp = mEdgeWaterObjects[dir];
            waterp->setIsEdgePatch(true);
            gPipeline.createObject(waterp);
        }

        waterp->setRegion(gAgent.getRegion());
        LLVector3d water_pos(water_center_x, water_center_y, 256.f + water_height) ;
        LLVector3 water_scale((F32) dim[0], (F32) dim[1], 512.f);

        //stretch out to horizon
        water_scale.mV[0] += fabsf(2048.f * gDirAxes[dir][0]);
        water_scale.mV[1] += fabsf(2048.f * gDirAxes[dir][1]);

        water_pos.mdV[0] += 1024.f * gDirAxes[dir][0];
        water_pos.mdV[1] += 1024.f * gDirAxes[dir][1];

        waterp->setPositionGlobal(water_pos);
        waterp->setScale(water_scale);

        gObjectList.updateActive(waterp);
    }
}


void LLWorld::shiftRegions(const LLVector3& offset)
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_PIPELINE;
    for (region_list_t::const_iterator i = getRegionList().begin(); i != getRegionList().end(); ++i)
    {
        LLViewerRegion* region = *i;
        region->updateRenderMatrix();
    }

    LLViewerPartSim::getInstance()->shift(offset);
}

LLViewerTexture* LLWorld::getDefaultWaterTexture()
{
    return mDefaultWaterTexturep;
}

void LLWorld::setSpaceTimeUSec(const U64MicrosecondsImplicit space_time_usec)
{
    mSpaceTimeUSec = space_time_usec;
}

U64MicrosecondsImplicit LLWorld::getSpaceTimeUSec() const
{
    return mSpaceTimeUSec;
}

void LLWorld::requestCacheMisses()
{
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        regionp->requestCacheMisses();
    }
}

void LLWorld::getInfo(LLSD& info)
{
    LLSD region_info;
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        regionp->getInfo(region_info);
        info["World"].append(region_info);
    }
}

void LLWorld::disconnectRegions()
{
    LLMessageSystem* msg = gMessageSystem;
    for (region_list_t::iterator iter = mRegionList.begin();
         iter != mRegionList.end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        if (regionp == gAgent.getRegion())
        {
            // Skip the main agent
            continue;
        }

        LL_INFOS() << "Sending AgentQuitCopy to: " << regionp->getHost() << LL_ENDL;
        msg->newMessageFast(_PREHASH_AgentQuitCopy);
        msg->nextBlockFast(_PREHASH_AgentData);
        msg->addUUIDFast(_PREHASH_AgentID, gAgent.getID());
        msg->addUUIDFast(_PREHASH_SessionID, gAgent.getSessionID());
        msg->nextBlockFast(_PREHASH_FuseBlock);
        msg->addU32Fast(_PREHASH_ViewerCircuitCode, gMessageSystem->mOurCircuitCode);
        msg->sendMessage(regionp->getHost());
    }
}

void process_enable_simulator(LLMessageSystem *msg, void **user_data)
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
    // enable the appropriate circuit for this simulator and
    // add its values into the gSimulator structure
    U64     handle;
    U32     ip_u32;
    U16     port;

    msg->getU64Fast(_PREHASH_SimulatorInfo, _PREHASH_Handle, handle);
    msg->getIPAddrFast(_PREHASH_SimulatorInfo, _PREHASH_IP, ip_u32);
    msg->getIPPortFast(_PREHASH_SimulatorInfo, _PREHASH_Port, port);

    // which simulator should we modify?
    LLHost sim(ip_u32, port);

    // Viewer trusts the simulator.
    msg->enableCircuit(sim, true);
    LLWorld::getInstance()->addRegion(handle, sim);

    // give the simulator a message it can use to get ip and port
    LL_INFOS() << "simulator_enable() Enabling " << sim << " with code " << msg->getOurCircuitCode() << LL_ENDL;
    msg->newMessageFast(_PREHASH_UseCircuitCode);
    msg->nextBlockFast(_PREHASH_CircuitCode);
    msg->addU32Fast(_PREHASH_Code, msg->getOurCircuitCode());
    msg->addUUIDFast(_PREHASH_SessionID, gAgent.getSessionID());
    msg->addUUIDFast(_PREHASH_ID, gAgent.getID());
    msg->sendReliable(sim);
}

class LLEstablishAgentCommunication : public LLHTTPNode
{
    LOG_CLASS(LLEstablishAgentCommunication);
public:
    virtual void describe(Description& desc) const
    {
        desc.shortInfo("seed capability info for a region");
        desc.postAPI();
        desc.input(
            "{ seed-capability: ..., sim-ip: ..., sim-port }");
        desc.source(__FILE__, __LINE__);
    }

    virtual void post(ResponsePtr response, const LLSD& context, const LLSD& input) const
    {
        if (LLApp::isExiting())
        {
            return;
        }

        if (gDisconnected)
        {
            return;
        }

        if (!LLWorld::instanceExists())
        {
            return;
        }

        if (!input["body"].has("agent-id") ||
            !input["body"].has("sim-ip-and-port") ||
            !input["body"].has("seed-capability"))
        {
            LL_WARNS() << "invalid parameters" << LL_ENDL;
            return;
        }

        LLHost sim(input["body"]["sim-ip-and-port"].asString());
        if (sim.isInvalid())
        {
            LL_WARNS() << "Got EstablishAgentCommunication with invalid host" << LL_ENDL;
            return;
        }

        LLViewerRegion* regionp = LLWorld::getInstance()->getRegion(sim);
        if (!regionp)
        {
            LL_WARNS() << "Got EstablishAgentCommunication for unknown region "
                    << sim << LL_ENDL;
            return;
        }
        LL_DEBUGS("CrossingCaps") << "Calling setSeedCapability from LLEstablishAgentCommunication::post. Seed cap == "
                << input["body"]["seed-capability"] << " for region " << regionp->getRegionID() << LL_ENDL;
        regionp->setSeedCapability(input["body"]["seed-capability"]);
    }
};

// disable the circuit to this simulator
// Called in response to "DisableSimulator" message.
void process_disable_simulator(LLMessageSystem *mesgsys, void **user_data)
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;

    LLHost host = mesgsys->getSender();

    //LL_INFOS() << "Disabling simulator with message from " << host << LL_ENDL;
    LLWorld::getInstance()->removeRegion(host);

    mesgsys->disableCircuit(host);
}


void process_region_handshake(LLMessageSystem* msg, void** user_data)
{
    LLHost host = msg->getSender();
    LLViewerRegion* regionp = LLWorld::getInstance()->getRegion(host);
    if (!regionp)
    {
        LL_WARNS() << "Got region handshake for unknown region "
            << host << LL_ENDL;
        return;
    }

    regionp->unpackRegionHandshake();
}


void send_agent_pause()
{
    // *NOTE:Mani Pausing the mainloop timeout. Otherwise a long modal event may cause
    // the thread monitor to timeout.
    LLAppViewer::instance()->pauseMainloopTimeout();

    // Note: used to check for LLWorld initialization before it became a singleton.
    // Rather than just remove this check I'm changing it to assure that the message
    // system has been initialized. -MG
    if (!gMessageSystem)
    {
        return;
    }

    gMessageSystem->newMessageFast(_PREHASH_AgentPause);
    gMessageSystem->nextBlockFast(_PREHASH_AgentData);
    gMessageSystem->addUUIDFast(_PREHASH_AgentID, gAgentID);
    gMessageSystem->addUUIDFast(_PREHASH_SessionID, gAgentSessionID);

    gAgentPauseSerialNum++;
    gMessageSystem->addU32Fast(_PREHASH_SerialNum, gAgentPauseSerialNum);

    for (LLWorld::region_list_t::const_iterator iter = LLWorld::getInstance()->getRegionList().begin();
         iter != LLWorld::getInstance()->getRegionList().end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        gMessageSystem->sendReliable(regionp->getHost());
    }

    gObjectList.mWasPaused = true;
    LLViewerStats::instance().getRecording().stop();
}


void send_agent_resume()
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_NETWORK;
    // Note: used to check for LLWorld initialization before it became a singleton.
    // Rather than just remove this check I'm changing it to assure that the message
    // system has been initialized. -MG
    if (!gMessageSystem)
    {
        return;
    }

    gMessageSystem->newMessageFast(_PREHASH_AgentResume);
    gMessageSystem->nextBlockFast(_PREHASH_AgentData);
    gMessageSystem->addUUIDFast(_PREHASH_AgentID, gAgentID);
    gMessageSystem->addUUIDFast(_PREHASH_SessionID, gAgentSessionID);

    gAgentPauseSerialNum++;
    gMessageSystem->addU32Fast(_PREHASH_SerialNum, gAgentPauseSerialNum);


    for (LLWorld::region_list_t::const_iterator iter = LLWorld::getInstance()->getRegionList().begin();
         iter != LLWorld::getInstance()->getRegionList().end(); ++iter)
    {
        LLViewerRegion* regionp = *iter;
        gMessageSystem->sendReliable(regionp->getHost());
    }

    // Resume data collection to ignore invalid rates
    LLViewerStats::instance().getRecording().resume();

    LLAppViewer::instance()->resumeMainloopTimeout();
}

static LLVector3d unpackLocalToGlobalPosition(U32 compact_local, const LLVector3d& region_origin)
{
    LLVector3d pos_local;

    pos_local.mdV[VZ] = (compact_local & 0xFFU) * 4;
    pos_local.mdV[VY] = (compact_local >> 8) & 0xFFU;
    pos_local.mdV[VX] = (compact_local >> 16) & 0xFFU;

    return region_origin + pos_local;
}

void LLWorld::getAvatars(uuid_vec_t* avatar_ids, std::vector<LLVector3d>* positions, const LLVector3d& relative_to, F32 radius) const
{
    F32 radius_squared = radius * radius;

    if(avatar_ids != NULL)
    {
        avatar_ids->clear();
    }
    if(positions != NULL)
    {
        positions->clear();
    }
    // get the list of avatars from the character list first, so distances are correct
    // when agent is above 1020m and other avatars are nearby
    for (LLCharacter* character : LLCharacter::sInstances)
    {
        LLVOAvatar* avatar = (LLVOAvatar*)character;
        if (!avatar->isDead() && !avatar->mIsDummy && !avatar->isOrphaned())
        {
            LLVector3d pos_global = avatar->getPositionGlobal();
            LLUUID uuid = avatar->getID();

            if (!uuid.isNull()
                && dist_vec_squared(pos_global, relative_to) <= radius_squared)
            {
                if (positions != NULL)
                {
                    positions->push_back(pos_global);
                }
                if (avatar_ids != NULL)
                {
                    avatar_ids->push_back(uuid);
                }
            }
        }
    }

    // region avatars added for situations where radius is greater than RenderFarClip
    for (const LLViewerRegion* regionp : LLWorld::getInstance()->getRegionList())
    {
        const LLVector3d& origin_global = regionp->getOriginGlobal();
        auto count = regionp->mMapAvatars.size();
        for (size_t i = 0; i < count; i++)
        {
            LLVector3d pos_global = unpackLocalToGlobalPosition(regionp->mMapAvatars.at(i), origin_global);
            if(dist_vec_squared(pos_global, relative_to) <= radius_squared)
            {
                LLUUID uuid = regionp->mMapAvatarIDs.at(i);
                // if this avatar doesn't already exist in the list, add it
                if(uuid.notNull() && avatar_ids != NULL && std::find(avatar_ids->begin(), avatar_ids->end(), uuid) == avatar_ids->end())
                {
                    if (positions != NULL)
                    {
                        positions->push_back(pos_global);
                    }
                    avatar_ids->push_back(uuid);
                }
            }
        }
    }
}

F32 LLWorld::getNearbyAvatarsAndMaxGPUTime(std::vector<LLVOAvatar*> &valid_nearby_avs)
{
    static LLCachedControl<F32> render_far_clip(gSavedSettings, "RenderFarClip", 64);

    F32 nearby_max_complexity = 0;
    F32 radius = render_far_clip * render_far_clip;

    for (LLCharacter* character : LLCharacter::sInstances)
    {
        LLVOAvatar* avatar = (LLVOAvatar*)character;
        if (!avatar->isDead() && !avatar->isControlAvatar())
        {
            if ((dist_vec_squared(avatar->getPositionGlobal(), gAgent.getPositionGlobal()) <= radius) ||
                (dist_vec_squared(avatar->getPositionGlobal(), gAgentCamera.getCameraPositionGlobal()) <= radius))
            {
                if (!avatar->isTooSlow())
                {
                    gPipeline.profileAvatar(avatar);
                }
                nearby_max_complexity = llmax(nearby_max_complexity, avatar->getGPURenderTime());
                valid_nearby_avs.push_back(avatar);
            }
        }
    }

    return nearby_max_complexity;
}

bool LLWorld::isRegionListed(const LLViewerRegion* region) const
{
    region_list_t::const_iterator it = find(mRegionList.begin(), mRegionList.end(), region);
    return it != mRegionList.end();
}

boost::signals2::connection LLWorld::setRegionRemovedCallback(const region_remove_signal_t::slot_type& cb)
{
    return mRegionRemovedSignal.connect(cb);
}

LLHTTPRegistration<LLEstablishAgentCommunication>
    gHTTPRegistrationEstablishAgentCommunication(
                            "/message/EstablishAgentCommunication");